Power-operated check valve



July 8, 1952 D. G. GRlswoLD 2,602,467

PowER-oPERATED CHECK VALVE Original Fled May 21, 1945 Patented July 8, 1952 UNITEDL STATS Bowancreencia CHECK VALVE I Donald G. Griswold, Alhambra, Calif., assigner to Clayton Manufacturing Company, Alhambra, Calif., a corporation of California Original application May 21,- 1945, Serial No. Y 595,007. Divided and this application May 21,

1945, Serial No. 595,004

y The present invention relates to check valves and more particularly to a power-operated (fluid pressure operated) check valve adapted to ybe employed in a backflow prevention unit such as ydisclosed in my application Serial No. 595,007, iiled of even date herewith, and of which the instant application is a division. However,

it is to be understood that the present valvev is not limited to use in a backflow unit.

The 'principal object of the invention 'is to provide a check valve which will close auto'- matically by gravity under a static line condi-V tion, and which can be positively closed held closed against line pressure by operating duid under pressure. Another object of the invention is to provide a pressurel fluid operated valve wherein it is iinv possible for the fluid in the pipe line in which the valve is connected to commingle with the operating duid for the valve, and vice versa. j A

Still another object of the invention is to provide a valve construction including means forv indicating that leakage is occurring along the valve stem from the outlet chamber of the valve. A further object of thevinvention is to provide a diaphragm valve including means for indicatV ing leakage along the vvalve stem connected with the diaphragm and for also indicating failure of the diaphragm.

Other objects and advantages of the invention will be apparent from the following description 1 claim. (o1. 1er-ses) said opening, and also has a lower radial flange 5l vin vertical alignment with' the boss 52. A

gasket lity is disposed vbetween the lower surface of the flange 5l and the boss 52 and a series of nuts 59 on the studs 53 secures the intermediate section 513Y to the body 45' and compresses the gasket 58 toA form a leakproof seal.'

The intermediate section 54 isprovided at its upper end with a radially extending flange 6)v that carries a series of studs tl. These studs' eX- tend through a flexible diaphragm ligand a flange 63 formed on the cover 55. A nutv lill threaded on each ofthe studs 0! clamps the marginal' portion oi the diaphragm 62 between the iianges E0 and 53 to thus secure the cover 55 and diaphragm h2 to the intermediate section 5A.

The cover E-is dished or recessed to provide a pressure or diaphragm chamber 55 yat the upper side of the diaphragm 62 adapted to Yre-A anda threaded portion l0 adapted to receivea self-locking nut 'H engageable with the plate taken in conjunction with the accompanying v drawing, in which the single ligure oi the drawing constitutes a View partly in section and partly in elevation of a combined gravity and power operated Vcheck Vvalve constructed in accordance with the principles of the invention.

Referring to the drawing, the Vfluid pressure operated, or power-operated, check valve is generally identilied by the letter B and comprises a valve body having an inlet opening or chamber 46 and an outlet opening or'chainber fil' separated by a partition 48. The partition ill is provided with a threaded opening A9 for the reception of a valve seat 50. The valve body 45 is further provided with a central opening 5l directly above the seat 50, said opening being surrounded by an annular boss 52 having a flat upper surface. A series of studs 53 is mounted in the boss 52.

' The valve B further includes a generally cuplike intermediate section 54 and a cover 55. The intermediatesection Fullhas a transverse lower or bottom wall portion 56 which overlies the opening 5l in the body 45 and forms a closure for 6E, whereby to maintain said main valvev stern section, plates and diaphragm in assembled relation. The main valve stem section 68 is prol vided with an axial passage 'l2 which telescopically and slidably receives the upper end of a second or auxiliary valvestem section 13. The auxiliary valve sternA section 'i3 is shouldered as indicatedxat 'M and projects through a valve disc l5. The valve disc i5 is provided with anannular recess 15a and has an annular sealing ring member 'It disposed in said recess which is cooperable with the seat 50 to cut off flow between the inletchamber 45 and the outlet chamber 41 of the valve B. A washer 'Il engages the inner portion of the lower side of the sealing ring T3 `to retainthe same in place. The auxiliary valve stem section V'I3 extends through the Washer l1 and is threaded at 13a for the reception of a self-locking nut 1 8 which secures rsaidvalve disc and washer to `said auxiliary valve stein section. Suitable spacing means, such as a ber washer lil, permits the necessary clarnp-v ing pressure to be applied to the disc l5 and" washer l1 Without undue distortion 'of thessaling member 16. The lower en d of the 'main valve stem sectionBB is adapted to' engage the shoul'V orties i i I means securing said lower flange of said intermediate section to said valve body and compressing said gasket to form a seal therebetween; a flexible diaphragm interposed between the upper flange of said intermediate section and said cover; means clamping the marginal portion of said diaphragm between said cover and said upper flange of said intermediate section and securing the same together in assembled relation, said cover being recessed to provide a pres# sure chamber above said diaphragm and having y passage means for admitting operating fluid into and exhausting operating fluid from `said pres,- sure chamber, said intermediate section having a transversely extending wall overlying and forming a closure for the opening in said valve body, said wall having a central boss; a main valve stem section connected to said diaphragm and extending through said boss; a bushing in said cover slidably receiving the upper end of said main valve stem section; a gland mounted in said boss and forming a guide for the lower portion of said main valve stem section; packing means carried by said gland normally forming a seal between said gland and said main valve stem section; packing means arranged to form a seal between said gland and said boss, whereby to prevent leakage from said outlet chamber into said intermediate section; means securing said main valve stem section to said diaphragm including a supporting plate disposed in said intermediate member at the lower side of said diaphragm, a supporting plate disposed at the upper side of said diaphragm and a nut threaded on said main valve stem section and engaging said last-mentioned supporting plate, said main valve stem section having an axial bore; an auxiliary valve stem section slidably received in said bore;

a valve disc carried by said auxiliary valve stem section; and sealing means on said valve disc cooperable with said seat to form a seal therewith to prevent flow through said valve body, said valve disc being adapted to seat by gravity independently of actuation of said diaphragm by REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 615,881 McIntosh Dec. 13, 1893 645,208 Mayer Mar. 13, 1900 '703,757 Bickford July 1, 1902 1,188,061 Franquist June 20, 1916 1,236,216 Schuler Aug. 7, 1917 1,369,444 Koplin Feb. 22, 1921 1,944,485 Andersen Jan. 23, 1934 2,233,395 Blanchard Mar. 4,' 1941 FOREIGN PATENTS Number Country Date 430,241 France Aug. 5, 1911 730,977 France May 24, 1932 

